Convert a Google Takeout JSON file to CSV table format

convert_to_csv.php

<?php

/**
 * Convert a Google Takeout JSON file to CSV table format
 * @author Owen Mundy owenmundy.com
 * Note: Make sure PHP has enough memory allotted on your system to handle large strings
 * Instructions:
 * 1. Download PHP file and place next to your JSON file
 * 2. Rename string pointing to your data file
 * 3. On command line run $ php index.php
 */

// get the contents of your JSON file
// rename string to point to your data file
$json = file_get_contents("data.json");

// convert to PHP object/array
$obj = json_decode($json, true);

// access specific data inside object
$locations = $obj['locations'];

// create string to hold finished CSV
$csv = "";

// add header to CSV
$csv += "data,latitudeE7,longitudeE7,accuracy,altitude\n";

// for testing (provides early exit for testing code on large data files)
$test = 0;
$limit = 0;

// loop through the PHP object
foreach ($locations as $key => $location) {
	
	// create temp var to hold current row
	$loc = "";
	
	// add data to row, with comma after each column...
	
	// add date, converting from timestamp (milliseconds) to human-readable date
	$loc .= date('Y-m-d H:i:s -0400', $location['timestampMs']/1000) .",";
	
	// add lat/lng
	$loc .= $location['latitudeE7'] .",";
	$loc .= $location['longitudeE7'] .",";
	
	// if accuracy and altitude are set then add, otherwise add empty string (comma)
	if (isset($location['accuracy']))
		$loc .= $location['accuracy'] .",";
	else
		$loc .= ",";
	if (isset($location['altitude']))
		$loc .= $location['altitude'] ."\n";
	else
		$loc .= "\n";

	// add this row to CSV
	$csv .= $loc;
	
	// for testing, if $limit defined and $test > $limit then stop
	if ($limit > 0 && ++$test > $limit) 
		die($csv);
}

// print the CSV to terminal
print $csv ."\n";

?>